Update: Today the FRBNY-Citadel tag team won. The spread which
started at an attractive basis, ripped wider and did not look back at
all. According to some desks, the main reasons for the assymetric
performance was early May window dressing (tomorrow markets will be
dead), as well as the 50 DMA VWAP. Additionally, as John Lohman shows
below, the correlation between the two legs settles at a 15 month low of
48%, indicating that everyone today was gunning stocks, even as they
were also buying bonds (sending yields lower), and not touching other
risk assets, in what can only be classified as a complete correlation breakdown. To those who were stopped out, there is always next week, especially since this divergence will eventually be forced to close.

Original post:

The now traditional mid-day attempt to boost stocks by the FRBNY has once again resulted in a substantial divergence between the ES (aka the S&P) and all other risk indicators (10y, curve butterfly, EURUSD, AUDJPY, Crude and Gold), the spread henceforth known as the "RISK spread" (courtesy of Capital Context), meaning that the "buyer" of last resort is throwing what little money it has left purely into ES keeping the stock market, aka the Russell 2000, aka the "Economy" afloat. Those who enjoy closing the spread divergence would be encouraged to take the opposite sides of this pair trade with the expected compression bent by EOD.